In an open-end spinning frame, the accumulation of fibers may prevent the smooth spinning operation and may cause yarn breakage and defective spun yarn. Therefore, it is advantageous to prevent such an accumulation of fibers. It is generally observed that when the spinning speed in an open-end frame is increased, the accumulation of fibers in the region neighboring the upper and lower surfaces of a fiber feeding mechanism is greater.
A device for preventing the accumulation of fibers in an open-end spinning frame is disclosed in U.S. Pat. No. 3,922,839. The device is intended to prevent the accumulation of fibers in the space between the free lateral surfaces of the feed roller and the combing roller and the inner surface of the closure plate covering the feed roller and combing roller in an open-end spinning frame. A groove is formed on the inner surface of the closure plate extending in opposition to at least the free lateral surfaces of the feed roller and combing roller, and one end of the groove is connected to an air suction source, which is either a channel for feeding combed fibers to the rotary spinning chamber, or a duct which discharges the air exhausted from the rotary spinning chamber. However, such an open-end spinning frame has the following disadvantages. Fibers which pass through the groove may stick at the portion adjacent to the side surface of the combing roller because of the rotational movement of the combing roller, and as a result, an accumulation of fibers may occur. Since part of the fibers pass by the combing roller without being subjected to a combing operation and are delivered to the spinning rotor, a yarn breakage or a defective spun yarn may result when a mass of fibers passing by the combing roller is delivered to the spinning rotor.